Inserting predefined pad values into a stream of vectors

Abstract

Software instructions are executed on a processor within a computer system to configure a steaming engine with stream parameters to define a multidimensional array. The stream parameters define a size for each dimension of the multidimensional array and a pad value indicator. Data is fetched from a memory coupled to the streaming engine responsive to the stream parameters. A stream of vectors is formed for the multidimensional array responsive to the stream parameters from the data fetched from memory. A padded stream vector is formed that includes a specified pad value without accessing the pad value from system memory.

The invention claimed is: 
     
       1. A method of operating a streaming engine in a computer system, the method comprising:
 receiving, by the streaming engine, stream parameters into control logic of the streaming engine to define a multidimensional array, wherein the stream parameters include a width indicator for a dimension of the multidimensional array, wherein the width indicator includes a width count; 
 generating, by an address generator, an address stream based on the stream parameters; 
 retrieving, by the streaming engine, a line of matrix data from a memory based on the address stream; and 
 forming, by the streaming engine, a stream vector in response to a status of the width count. 
 
     
     
       2. The method of  claim 1 , wherein:
 the status of the width count is depleted. 
 
     
     
       3. The method of  claim 2 , wherein:
 the status of the width count is not saturated. 
 
     
     
       4. The method of  claim 3 , wherein:
 the stream vector is formed by masking a portion of the stream vector that exceeds the width count. 
 
     
     
       5. The method of  claim 4 , wherein:
 a value of zero is inserted in the portion of the stream vector that is masked. 
 
     
     
       6. The method of  claim 4 , wherein:
 a predefined value is inserted in the portion of the stream vector that is masked. 
 
     
     
       7. The method of  claim 6 , wherein:
 the predefined value is one of a minimum value and a maximum value. 
 
     
     
       8. The method of  claim 2 , wherein:
 the status of the width count is saturated. 
 
     
     
       9. The method of  claim 8 , wherein:
 the stream vector is a null vector formed without accessing the memory. 
 
     
     
       10. The method of  claim 9 , wherein:
 the null vector is all zeros. 
 
     
     
       11. The method of  claim 9 , wherein:
 the null vector is a predetermined value. 
 
     
     
       12. The method of  claim 11 , wherein:
 the predetermined value is selected from one of a minimum value and a maximum value. 
 
     
     
       13. The method of  claim 11 , wherein:
 the predetermined value is designated by a flag value in the stream parameters. 
 
     
     
       14. The method of  claim 1 , further comprising:
 decrementing the width count. 
 
     
     
       15. The method of  claim 14 , further comprising:
 in response to matrix data remaining to be retrieved, retrieving, by the streaming engine, a next line of the matrix data. 
 
     
     
       16. A system, comprising:
 a system memory; 
 a streaming engine coupled to access the system memory, the streaming engine configured to:
 receive stream parameters defining a multidimensional array, wherein the stream parameters include a width indicator for each dimension of the multidimensional array, wherein the width indicator includes a width count; 
 generate an address stream based on the stream parameters; 
 retrieve a line of matrix data from the system memory based on the address stream; and 
 form a stream of vectors in response to a status of the width count of the width indicator; and 
 
 a processing unit coupled to outputs of the streaming engine to receive the stream of vectors. 
 
     
     
       17. The system of  claim 16 , wherein:
 the status of the width count is depleted and not saturated. 
 
     
     
       18. The system of  claim 17 , wherein:
 the stream of vectors is formed by masking a portion of the stream of vectors that exceeds the width count. 
 
     
     
       19. The system of  claim 16 , wherein:
 the status of the width count is depleted and saturated. 
 
     
     
       20. The system of  claim 19 , wherein:
 the stream of vectors includes a null vector formed without accessing the system memory.